Crankcase breather construction



Jan. 16,1940. w. CARLSO'N' 2,187,265

CRANKGASE BREATHER CONSTRUCTION Filed Jan. 24;"193a 1o determined degree.

rimmed J 'ie, 1 40 7 2 1 7 265:

IUNITEDISTATES PATENTTOFFICE l CRANKCASE BBEATHER CONSTRUCTION Wilbur OarlsomRochester, N. n, assignor to General Motors. Corporation, Detroit, Mich, a corporation of Delaware Application January 24, 1938, Serial No. 186,579

I 80laims. (Cl.--121-194) This invention relates to a new and improved when the breather unit is associated with the crankcase breather construction for internal engine, as of generally cup-shaped form with-an combustion engines which is adapted to relieve outwardly extending flange I4 at its open end, the compression in the crankcase. I and is provided with a series of openings IS in 5 It isone of the objects of the invention to its peripheral wall and also with'a relatively i" provide a breather construction with a valve small hole IE for a function to be hereafter dewhich will permit the escape oi gases and vapors scribed. I from the crankcase to the atmosphere whenever .The casing member In, which is located outthe pressure in the crankcase exceeds some preside of the crankcase when the breather unit I is associated with the engine, is also of generally A further object is to provide a breather concup-shaped form with an offset flange I! at its struction which will separate any oil from the open end which is crimped or spun over the flange crankcase gases and vapors passing through the 14 of the casingmember 9 as shown in Figure 2, breather and return this oil to the crankcase. during assemblyof the breather unit. This cas- 15 I Itis a still further object toprovide a'breather ing member In is providedwith a peripheral ll construction which is exceedingly simple and inslot l8 which is formed with the outwardly curved expensive to manufacture. I A wall portion N in the nature of a louver. Other objects and advantages of this inven I The plate member H is a flat circular plate tion will'appear from the following description having a diameter substantially equal to the V taken in, connection with the accompanying outside diameter of the flange M on the open end 20 drawing, in which: I of the casing member 9 and this plate is provided "Figure l is a iragmental vertical section of. an with a plurality of slots 20 and witha relatively internal combustion engine with the breathr of small hole 21 adjacent its edge for a purpose to the present invention. be later set forth. I r

, Figure 2 is a vertical, longitudinal section. of The valve member l2 whichis of relatively thin 25 I breather casing in elevation.

the breather assembly with a portion of the sheet metal, such as spring steel, is formed with I a a base portion which may be secured as. by rivets Figure 3 is-a transversesection oithe breather 22 to the plate member H with a metal washer assembly taken'substantially on line 3-4 ofFig- 23 interposedbetween each rivet head and the I I y member, l2, and. with a plurality of upstanding I0,

Figure its a perspective view 01 certain eleears 24 which are in the nature of spring reeds mentsof-the breather assembly shown in spaced and which are slightly-larger than the slots 20 relation. I I i v I v in the plate member H and biased to normally Referring first to Figure 1, the breather unit, -close such slots.

"'85 indicated generally at I, is shown in connection "The filter retaining member i3 is a dished cirwith an air cooled engine 2 of the general type cular plate having" a diameter equal to that oi 'usedin small electric generating plants, although i the plate member H. The dished, centralpo'rit willbe understoodth'at this breather unit may tion of this member I3 is, provided with the ina he used. with. any standard internal combustion q gclined louvers 25 and with a relatively small hole 5 the present invention.

-40 engine. In the present showing, the engine "2 Y 26 adjacent its offset peripheral edge.- The filter m I includes the usual cylinder 3, piston 4', connect-- element which may consist of a mass of copper I ing rod 5; crankshaft 6, and crankcase '1, and the mesh or other suitable perv'ious material 21, .is "crankcase is provided with an opening -I tore. adapted to be located within the casing memv ceive the breather unit I. which isthe subjectoi 1 berJll r- I I I I 1 To assemble the breather unit, the circular 5 I With the exception o! a element, the edge'of the member I 3 is placed within-the offset I entire breather unit is made up otfsheet metal flange H on the casing member It with the parts which maybe cheaply andreadily formed dished, central portion oi this member l3 extend- 1 -'and assembled with the iilterfelement in a seliing towards and engaging the filter materialll,

- contained unit as isshown in'YI Ig ure 'Z. These the plate member I I is then p aced -againstthe so metal parts 'cbnsist or the two casing members member 53 with its circular edge also within the- I 9 and I0, the plate member :lLthe valve mem- I ofiset flange I'l on the casing member "I and", bet i2, and the filter retaining member l3. 1 with itsattached valve member I! on the side,

' Thecasing member 9, which asshown in Figtowards the member 13, and the flange H of the ,5; .ure 1 isadapted to extend into the crankcase l casing members is then placed against the plate.

1 In the present application of the invention, the

crank pin bearing and crankshaft hearing are adapted to be lubricated by a splash system and the hollow connecting rod 5 is provided with an' 15 extension to splash the'oil'in. the crankcase and also'feed some of this oil through the connecting rod to the piston pin bearing (not shown), and it is preferable to provide a horizontal bafiie plate or wall 28 in the crank case below the opening 8 therein'for the breather unit to prevent the direct splashing of oil into the openings iii in the breather casing member 9 which extends into the crankcase.

' nth the above described construction it 1! now be apparent that the crankcase gases and vapors may first enter the casing member 9 of the breather unit through the openings 95- and whenever the pressure thereof deflects the spring reeds fl, pass'through the slots in the plate memso her H into the space between this member and the filter retainin'grmember l3. From here the gases and vapors may escape to the atmosphere by passing through the louvers 25 in the member l3 whichfunctions as a bafile member and dig through the filter material 2? to the outlet slot L8 in the casing member iii. I

During this movement of the crankcase gases and vapors to the atmosphere it will also be apparent that the relatively small amount of oil All; which maybe present in these vapors will either condense on some of the interior surfaces or be separated from the vapors by the filter material 21, and may be returned to the crankcase through the small holes adjacent the bottom'of. members 5,- 9, H and t3, For instance, any oil which collects in the bottom of the casing member it may pass through the hole 26 in member is, and together with any oil which collects in thebottom of the space between member 33 and member ll,

5;, then pass through the hole 2i in member it; into the casing member 9 and together with any oil,

which has collected therein, be returned to the crankcase through the drain hole N3.

It will also be apparent that whereas the valve member l2 opens only outwardly to provide a relatively large passage to relieve excess pressure one way pressure operated valve for the passage in the crankcase, the slot I8; oil drain holes is and 2|, and louvers 25 provide a relatively re'- drawn into the crankcase through this passage together with any crankcase gases and vapors and condensed oil in the breather unit, a 5

As has been noted above, the louvers- 25 in th filter retainingmember I-3 are inclined or diagonal-ly arranged with-reference to the horizontal axis of this member, and this member not only prevents the filter material 2.1- iromcontacting the valvmmember 42 but alsoliunctions as a bafile member and condenses some of the cal vparticles in the crankcase vapors. Such on particies as are condensed on the surface of the filter u retaining member is will drain downwardly thereon to be returned to the crankcase through the openings 2| and [6. The inclined arrangement of the louvers 25 provides for the downward draining of the condensed oil and reduces the collection of oil particles on the bottom edge of 6 the louvers. If the louvers'were horizontally arranged there would be a tendency for the oil to collect on the bottom edges of the l'ouvers and pass through the louvers into the filter chamber.

It will therefore be apparent that the filter re- 10 taining member/13 and the diagonal arrangement of the louvers 25 serve to reduce the amount of oil which passes to the filter material to be separated thereby from the gases and vapors which escape to the atmosphere through the outlet slot i8.

I out to the atmosphere on violent surges such as are causedby-the movement of the piston :3. -Un-- less the outlet slot i8 is materially smaller in size than theother'. passages in the breather unit for the crankcase gases and vapors, it has been found that some oil particles will be expelled through 39] this slot. as

Only asingle specific embodiment of the inventionhas been herein shown and described, but it will be understood that the invention is not to be strictly limited thereto and various changes .5. and modifications may be made within the scope of the invention as set forth inthe appended I claims;

I- claim: I i -1.- In a crankcase breather, a casing adapted to communicate with a crankcase adjacent one end oi saidcasing andwith the'atmosphere adjacent the other end. of said casing, a wall intermediate the ends of said casing provided with a one-way pressure operated valve for the passage of crank- 45 case vapors from the crankcase tothe atmosphere, filter material in said casing between said valve and-the outlet to the atmosphere to remove oiltiro'rn said vapors, and means interposed betweensaid wall and said filter material to space said material from said valve.

2. In a crankcasebreather, a casing adapted to communicate with a crankcase adjacent one end of said casing and with the atmosphere adjacent the other and or said casing, a wall-i-nter- 55 mediate the ends of said casing provided with a q i cran kcase vapors from the crankcase to the atmosphere, filter material in said casing between said valve and the outlet to the atmosphere toga remove-oil from said vapors, and a filter retaining L plate interposed between said wall and saidfiltcr material and louvres in said plate to provide tor the passage of crankcase vapors therethrough. 3. In a crankcase breather, a, casing adapted to as communicate witha crankcase adjacent one end of. said casing and with the atmosphere adjacent the other end ofjsaid casing, a wall intermediate the ends of saidrcasing provided with a one-way pressure operated valve for the passage of crank- '10 case'vapors from the crankcase to the atmosphere; filter materlal in'said casing between said valve and the outlet to the atmosphere to remove oil tron! said vapors, solidwall being provided with an opening adjacent the bottom thereof and said gs I 1 the other end of said opening in said casing being provided with a drain hole to permit the return of oil from said filter material to the crankcase.

4. In a crankcase breather, a casing adapted to communicate with a crankcase adjacent one end. of said casing and with the atmosphere adjacent casing, a wall intermediate the ends of said casing provided with a one-way pressure operated valve for the passage of crankcase vapors from the crankcase phere, filter material in said casing between said valve and the outlet to the atmosphere to remove oil from said vapors, a filter retaining plate interposed between said wall and said filter material, and relatively small openings in said wall and plate adjacent the bottom thereof with a drain hole in said casing adjacent the end thereof which communicates with the crankcase to permit the return of oil to the crankcase.

5. In a crankcase breather, a casing constituted by' two substantially cup-shaped parts to provide a substantially cylindrical casing with closed end walls, peripheral openings in said casing adjacent opposite ends thereof adapted to communicate respectively with a crankcase and the atmosphere,

a wall intermediate the ends of said casing and clamped between the two parts thereof, and an wall with a spring reed secured to said wall and normally closing said opening.

6. In a crankcase breather, a casing constituted by two substantially cup-shaped parts to provide a substantially cylindrical casing with to the atmosclosed end walls, peripheral openings in said casing adjacent opposite ends thereof adapted to communicate respectively with a crankcase and the atmosphere, a. wall intermediate the ends of said casing and provided with an opening cured to said wall and normally closing said opening, filter material in said casing between said wall and the outlet to the atmosphere, and a filter retaining member interposed between said wall and said filter material and provided with louvres, said wall and said filter retaining member being clamped between the two parts of the casing.

7. The elements set forth inclaim 6, with relatively small openings in said wall and filter retaining member adjacent the bottom thereof and a-bottom drain hole in said casing to permit the return of oil from said filter material to the crankcase. I 8. In acrankcase breather, a casing adapted to communicate with a crankcase adjacent one end of said casing and with the atmosphere adjacent the other end of said casing, a wall intermediate the ends of said casing provided with a one-way pressure operated valve for the passage or crankcase vapors from the crankcase to the atmosphere, filter material in said casing between said valve and the outlet to the atmosphere, a filter retaining plate interposed between said wall and said filter material and louvers in said plate, said louvers being diagonally arranged with reference to the horizontal axis of said plate. v WILBUR L. CARLSON.

with a spring reed se- 

